I'd leave the 27's on the Caliente. As EjustE mentioned 27 x 1-3/8 is the largest size tire you'll find in 27"....sort of. All tire are measured differently, a 1" in one companies line may measure differently than another companies 1" tire. The reason I mention this is because the Bell 27 X 1 1/4" tires from WalMart are HUGE.